Thyroid function and circulating antithyroid antibodies in myasthenia gravis.
Evaluation of thyroid function in 104 patients with myasthenia gravis by T3, T4, TBG, and TSH radioimmunoassays and the TRH-stimulation test in 47 patients disclosed thyrotoxicosis in 5.7%, preclinical hyperthyroidism probably due to autonomously functioning thyroid tissue in about 10% of patients stimulated with TRH, hypothyroidism in 1.9%, and preclinical hypothyroidism in 3.4%. Eighty-four percent were euthyroid. Antithyroid antibody activity was detected by hemagglutination tests. Twelve patients had antithyroglobulin antibodies (Tab), and 28 had antimicrosomal antibodies (Mab). Among the euthyroid myasthenic patients, 7 were Tab-positive and 20 were Mab-positive. Euthyroid antibody-positive patients had a significantly higher TSH response in the TRH stimulation test and may be at high risk for hypothyroidism.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000097:blood / Q000150:complications* / Q000276:immunology; D013959:Thyroid Diseases / Q000097:blood / Q000150:complications* / Q000276:immunology; D013961:Thyroid Gland / Q000276:immunology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013975:Thyroxine-Binding Proteins / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001323:Autoantibodies; D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine